<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
<div id="demo">
  <ol contenteditable style="border: 1px solid red">
    <li>111111</li>
  </ol>
</div>
</body>
<script>
  const MutationObserver =
    window.MutationObserver ||
    window.WebKitMutationObserver ||
    window.MozMutationObserver
  const list = document.querySelector('ol')
  const Observer = new MutationObserver((mutations, instance) => {
    mutations.forEach(mutation => {
      if (mutation.type === 'childList') {
        const list_values = [].slice
          .call(list.children)
          .map(node => node.innerHTML)
          .filter(s => s !== '<br>')
        console.log(list_values)
      }
    })
  })
  Observer.observe(list, {
    childList: true
  })
</script>
</html>
